Template fix when journal missing information.

Strange fact: hakyll templates don't report missing fields sometimes,
under conditionals?

templates/bibitemtpl.html

@@ -8,7 +8,11 @@
       In $booktitle$.</br>
     $endif$
     $if(journal)$
-      $journal$, $volume$($number$):$pages$, $month$ $year$.</br>
+      $journal$, 
+      $if(pages)$
+        $volume$($number$):$pages$,
+      $endif$
+      $month$ $year$.</br>
     $endif$
     $if(url)$
       [<a href="$url$">Paper</a>]